Hi, I've got a bit of a problem with my 98 TJ 4.0l 5 speed.
Here's what happens...
Around town, all is fine, but once I get on the highway for a while at consitantly higher rpms...around 2200 or so..at 65mph in 5th, it will randomly, and without notice suddenly start to sputter, does a small backfire, and the rpms drop immediatley. Adding gas does nothing but drop the rpms faster, and all I can do is pull off the road before being forced to a stop in the middle of the highway. It doesn't die, but will just sputter away at just under regular idle speed. I have found that I can shut it off, and let it sit for a minute, then restart..(no problems restarting), and I can sometimes continue for a while, sometimes just a few hundred yards before it does it again. If I can get to an exit, I can drive it all day around town with no problems.
Here's what i've done so far...
I changed the plugs, wires and distributor cap...no effect
It did it once on the way to a job appointment, so I had to limp it to the nearest dealer, and got a quick rental while they took a look at it. They of course could not duplicate the problem, but they ran a minimum air flow test and it failed that, so they did an induction service, emisions flush, and clenaed the throttle bore and induction system of carbon deposits. $125...I was glad to get out of the dealer with a bill that low..lol, and I hoped that just maybe, that was the problem. Yep, you guessed it...no effect!
Has anyone experienced this type of thing before, and can advise me furthur?
Any help is appreciated.
Regards, Kelly